engraving a dome

[monstrol]

Like the prefix says...newbie. Is it possible to engrave a dome? I am still
researching which benchtop to purchase. This may be a software question as well, I just don't know. I am looking at a General 40-915x and a Probotix fireball comet and I realize in the CNC world these are smaller machines. I will post in the software section as well. Thanks in advance.
Matthew

[louieatienza]

With the right software, yes! In Aspire, you can engrave (or do raised lettering) on a 3D surface. I do engrave toolpaths on curved surfaces regularly with OneCNC.

Of course, if the dome alread exists, you'd have to model it pretty accurately to get the text to engrave correctly.

[yohudi]

Hi There,

A FREE multi axis tool called cnc_toolkit will engrave on a dome..

It does so by 'wrapping' or projecting your engrave path onto the domed surface
.. the output from cnc_toolkit is essentially just the axis motion.. with some basic commands ... nothing out of the ordinary.... so should be compatible with most machinery...

The process used is described at Rab Gordon's cnctoolkit blog.. he recently applied the technique to adapt a V-Carving path to an uneven surface... it's not a dome by any means... but the same principles would address a domed surface ...

the link to the job description with photo's and info is below..

CNC Toolkit - Free Utilities for Multi-Axis Machining

hope this helps

Danny

EDIT:.

I've added the link to the CNC_Toolkit gallery at my site.. images 16 and 17 should give you an idea of the type of thing that is possible...

CNC_Toolkit Image gallery

TTFN

Danny

[monstrol]

With the right software, yes! In Aspire, you can engrave (or do raised lettering) on a 3D surface. I do engrave toolpaths on curved surfaces regularly with OneCNC.

Of course, if the dome alread exists, you'd have to model it pretty accurately to get the text to engrave correctly.

Thanks for the reply. I was thinking about turning a dome on my "analog lathe" using the dimensions of a virtual dome created with some software, importing that to get a gcode, creating a toolpath, designing a skin to fit and going to town, I said I was a newbie. Is this even possible? Thanks again.
Matt

[monstrol]

Hi There,

A FREE multi axis tool called cnc_toolkit will engrave on a dome..

It does so by 'wrapping' or projecting your engrave path onto the domed surface
.. the output from cnc_toolkit is essentially just the axis motion.. with some basic commands ... nothing out of the ordinary.... so should be compatible with most machinery...

The process used is described at Rab Gordon's cnctoolkit blog.. he recently applied the technique to adapt a V-Carving path to an uneven surface... it's not a dome by any means... but the same principles would address a domed surface ...

the link to the job description with photo's and info is below..

CNC Toolkit - Free Utilities for Multi-Axis Machining

hope this helps

Danny

EDIT:.

I've added the link to the CNC_Toolkit gallery at my site.. images 16 and 17 should give you an idea of the type of thing that is possible...

CNC_Toolkit Image gallery

TTFN

Danny

Thanks Danny I will check these out!
Matthew

[adprinter]

Like the prefix says...newbie. Is it possible to engrave a dome? I am still
researching which benchtop to purchase. This may be a software question as well, I just don't know. I am looking at a General 40-915x and a Probotix fireball comet and I realize in the CNC world these are smaller machines. I will post in the software section as well. Thanks in advance.
Matthew

I designed and built my own machine. Which is pretty common on this forum. Your question about engraving on a dome is possible using one of my favorite programs: MeshCAM Art! I actually learned how to do this, from one of the other users on the MeshCAM forum- you work with bitmap images in MC Art, and the secret to engraving a dome shape, is to create the engraving in a contrasting color on the artwork in 2D (for example, create a circle filled with BLUE, and insert some text which is RED).

Then, import the image into MC Art, and open the Shape Editor window. Select both colors (the BLUE and the RED) and specify a starting depth of say -.75" Angle of 60 degrees, Shape Round, Height Limit None, then select OK to process. After a few seconds, the image will appear as just a smooth dome shape (the engraving will not be visible on the surface of the dome, at this point).

Next, go back into the Shape Editor, and select just the RED color, and click OK to open the Shape Editor window. And set everything up as follows:
Shape=Angle
Angle=1 degree
Starting Height=(your desired cut depth as a POSITIVE number)
Height Limit=None
Subtract
click OK
After a few seconds, your engraving will appear on the surface of the dome.